Quick release clamp



Feb. 27,, 1951 HAGAN 2,543,017

QUICK RELEASE CLAMP Filed June 23, 1945 INVENTOR JOHN A. HAGAN ATTORNEY Patented F eb. 27, .1951

.TQUICKRELEASE I CLAMP .EI'ohmAJHagan; United statesNavy, iQuincy, Mass.

v..ApplicatiOn-TQJuneT23, 1945, SeriallNo. 501L280 lfiranted under the act of .March .3, .1883, "as amendedApriLBO, 1928; .370 0. .G. 757) This invention relates tto mlamps (for :handling heavy :plates and iis illustrated :herein :as :embodied in1a clamp which can the :attached to 5a plate firmly and quickly "and which roan be *re-' leased quickly.

Heavy :plates :of ;metal are edifficult to :hanfile because of theirxunwieldlyfsizesandggreat weight. A common type of .clampzusediiorfharrdlingi'metal plates is 1 one lVhiGhLiS :constructed :withea pair of jaws which :..are zxfo'rced :.by :a ;:linkage within Zthe eclamp "to ttighten on :a rplate when Ia pull isexertedmntherclamp. lZEhe platesisqgripped by .the .clamp 'onlyzwhen ith'ere 'a pull exerted on the :Zlinkage and ::away :from :the plate to be gripped. This type of clampican rbze fi-xed to a plate TOIIIGIIIOVEII- there'fromaquickly'xbut :it is .unsatisfactory for fieveral 51368250115. E'irstly, the clamp :releases .sud'denly :the plate :carried byiit I is lowered to the ."groimdmr 4103171165 deckiofia ship, and :the *clampzmayzbezre'leased?by:mistale. Moreover, this type of clamp is ieas ily .loosened once the pull thereionzisrelieved. :Expertrcare'by the operator iis :required lto 'cprevent :accidents caused. by'unexpectedly iallingzplates'which may injure personnel and damage mearby material. In addition, zit :is not possible 1 .130 at. attach a clamp 01" this type ;in :a: satisfactory zmanner zto 5a ixplate which :is aflat 1011 the grounirl aor ton ta (deck zbecause, when fa plate is ';so i'disposed, it .is Jdifiicult toz'attachaaeclamp'..thereto:inis1ich2a:manner that there 2 is an .initialzpull on the clamp; in ca proper direction to rcause Littto grip *sthe qalate.

5111 view of :the :lforegoing, fit is ca rprincipal :ebject -'.of this invention ;to .provide fa uclamp :for handling "heavy i'metalrplates *which man .guickly, yet: firmly, 'be attached to :a {plate It is a further object of thisiinventionato-provide foritherspeedytremovalidfisuch :a :clamp.

It is .a iur'th'er 1 oby'iect ro'ftthis invention ato rprevent :the accidental frelease of such 2a :clamp.

JATfllIthEI'iObjGCt Qffthis inventionzis .:to provide aeclamp whichican bezattachedto;azplatetsecurely .withoutiapplying a hoistingfiorce'to .thea'clamp.

.Accordingly, :this invention zprovi'des, fin clamp havinga .pairo iiawsroneiiof which is :movable to grip :01 (hold f-an aob'ject 'itherebetween .in response .to :a pull exerted ion is. :bol-t i-associated with zithe jaws, :"a imeans ffor flocking ithe bolt against :reverse movement. ithe :illustrated clamp, the pull:isiproducediindepmtlentlypf 'any hoisting1force byzmeans-rof c-a' nutvthreadedi'to'the shank of the ::bolt (and adapted zto ibear .upon ;:a casing of:the'c1am,p.

The jaws of a clamp provided inaaccordance with this invention are {positively closed and 2 locked-.inplace uponzan object held by them. Moreover, the clamp not only can be attached to or released :from a heavy jplate quickly, but also .is firmlyffixed .to the plate once it is at-- tached thereto.

-Wi.th.'theabove and other features and obiects in View, :the invention will: now :loeadescribed With reference :to the accompanying .drawings which illustrate a preferred embodiment of the invention and will be pointed out in the claims.

Fig. 21 is :a front elevational'view'ofia clamp constructed in accordance with :this vinvention, the :clamp being shown in position to :grip .a metal :plate, part of the casing of the clamp being broken away 1 to show the internal j linkage.

Fig. Zzisa side elevational View of the clamp shown in :Fig. 11, the casing being cut away to show i the 1 internal linkage.

.:llig. :is :a .front elevational view of ."another clamp :constructed :in accordance with this invention, :the internal linkage "being shown by dotted lines.

:AS illustrated in .Figs. .1 and 12, the "clamp "includes acaing .1 *whichris hollow .;and through which 'four openings arecdrilledito take four :bolts 3,15, l,':and 9,'which1-support aalinkage inside :the casing and formlpivots around which the-moving partsaof the linkage swing.

iIn:.Eig. 1 the right hand half of thecasing'is brokemaway .to show-the linkage within. Inside theleftihandside tof the leasing there is'a klinkage similar :to that .in the :right ihand side, :and, therefore, only the right Than'd linkage 'Will aloe described in vdetail.

The right hand linkage:includesraipairof arms IE! and I I. One .end of each/arm sis connected to .the other 'arm'by :a pin l3. Rivoted :to 'the OthElfGIld; of therarm 'I I .is a jaw lfiwhichswings around the 'bolt 9. .The'arm H1 pivotsiaround the bolt 5? which fits through a slot 1.5 tin the-"arm .1!) to f'iorm ta .rfulcrum about which the arm 12] swings,;as.clearlyshown inFig. 1. EheIlei-t hand end *iof the'arm ;l0:is:'pivotally attached to..a bolt F! by-atpin l8 zaLt-theabottomtdf the bolt. The bOItTZJCtSithI'Ollgh the'arms l0 and I i 130013811501 close the jaw :l 5. WhEHithE bOIt ll ispulled outwardly :of .the casing, the :linkage .drives the jaw [5"130Ll1h6118f11 into position to grip ta aplate :19, of which :only a .portion is .shown. .Conversely, when the bolt :descends, :the .jaw rmoves to fthe right into released position.

are forced together to grip the plate [9. On the other hand, when the pull on the bolt I! is released, the grip of the jaws on the plate also is released.

An annular ring 23 forms the upper part of bolt I'!. A crane hook or other lifting device is attached to the ring to lift the clamp together with the plate.

The shank of the bolt I1 is threaded as shown in Figs. 1 and 2 to carry a nut 25. The lower surface of the nut 25 bears upon the upper surface of the casing I to exert a pull on the bolt I? and lock the bolt in position to prevent release of the jaws. A pair of arms 26 and 21, attached to the nut 25, facilitates the turning of the nut.

The upper surface of the casing is constructed with a radius A which is relatively longer than the radius B through which the lower surface of the nut 25 swings about the linkage, as shown in Fig. l. The upper surface of the casing l forms an abutment against which the nut 25 is frictionally locked when it is set up to exert a pull on the bolt 11. Moreover, when the nut is in looking position, a pull on the ring 23 in any direction which causes the bolt H to swing about the pin [8 creates an additional tightening of the jaws on the plate I9 owing to the wedging action between the nut 25 and the upper surface of the casing l.

The clamp described can quickly and easily be attached to a plate. The clamp is placed upon the plate with the jaws engaging the opposite sides of the plate as shown in Fig. 1. Then, the nut 25 is rotated with the aid of the arms 26 and 2'! until it bears on the upper surface of the casing. The nut can normally be turned by hand without the aid of special tools. However, it may be necessary to give the nut a blow with a hammer to lock it firmly in place. The clamp can be attached as described in a few seconds. The nut 25 exerts a continuous pull on the bolt l7, and, as already pointed out, the lifting pull serves to tighten the grip of the jaws and hold the clamp in place on the plate regardless of the direction of the initial lifting pull. Thus, the clamp can be attached satisfactorily to a sheet which is flat on the ground. Moreover, the clamp does not release automatically as soon as the plate carried by it touches the ground or the deck of a ship, and the clamp cannot be knocked loose accidentally by anything less than a blow on one of the arms 26 and 2'! which causes the nut 25 to turn to release the locking effect combined with a violent contact of the bottom of the plate 19 with the ground or a deck. This possibility is very remote because of the protection afforded the arms 26 and 21 by the wide front of the easing I (Fig. 1) and by the plate [9, carried by the clamp, which extends perpendicular to the narrow side of the clamp (Fig. 2). On the other hand, when it is desired to release a plate carried by the clamp, the clamp can be removed quickly at any time when the lower portion of the plate rests on a solid surface. The nut 25 is rotated to move up the bolt l1 outwardly of the clamp either by turning by hand or by a blow of a hammer to release the pressure between the jaws l and 20, thus releasing the grip of the clamp on the plate and permitting it to be removed therefrom.

Fig. 3 illustrates a clamp of the same general type as that already described but of somewhat simpler construction. The clamp shown in Fig. 3 is suitable for carrying relatively lighter loads 4 than the one illustrated in Figs. 1 and 2. This second clamp comprises a casing 3| having a stationary jaw 33, and carrying a bolt 35 on which a jaw 3'! is pivoted. The casing is bored slidably to receive a bolt 39 on which is threaded a knurled nut 4|, the latter being adapted to bear against the top of the casing 31. A link 43 is pivotally connected to the bolt 39 and the jaw 3'! at 45 and 41 respectively. The nut 4| can be turned with the fingers to force it to exert a pull on the bolt 33. An annular ring 49 which forms the upper portion of the bolt 39 provides means for connecting the clamp to a crane hook to left the clamp together with a metal plate gripped by the jaws.

A clamp constructed as shown in Fig. 3 has been found suitable for carrying loads of a ton or more. On the other hand, clamps of the type illustrated in Figs. 1 and 2 are satisfactory for handling much greater loads.

The invention described herein may be manufactured and used by or for the Government of the United States of America for government purposes without the payment of any royalty thereon or therefor.

Having thus described my invention what I claim as novel and desire to protect by Letters Patent of the United States is:

1. A clamp comprising a casing, a pair of jaws, said jaws bein movable to form a bite with each other, a bolt, means comprising links to which said bolt is pivoted connecting one end of said bolt and said jaws for forcing said jaws toward each other when a pull is exerted on said bolt, and a nut for exerting a pull on said bolt, said nut being threaded to the shank of said bolt and adapted to bear on said casing, the radius of curvature of the portion of said casing upon which said nut bears being greater than the radius through which said nut swings with respect to said link.

A" clamp comprising a' casing, a pair of jaws operatively positioned within said casing, said jaws being relatively movable to form a bite with each other, a bolt, means comprising links to which said bolt is pivotally secured and connecting said bolt and said jaws for forcing said jaws toward each other when a pull is exerted on said bolt, a nut, said nut being threaded to the shank of said bolt and adapted to bear on said casing, said casing having an external curvature which precludes relative rotation between said bolt and said casing in the plane of said links about the point of connection of said bolt to said links when said nut bears on said casing and which permits said relative rotation when said nut is free of said casing.

3. A clamp comprising a substantially flat casing, a pair of jaws pivotally supported within said casing, said jaws being relatively movable to form a bite with each other, a bolt, means comprising a pair of first links pivotally connected to said bolt and a pair of second links pivotally connected between said first links and said pair of jaws for interconnecting Said bolt and said jaws, said links being arranged whereby said jaws are urged toward each other when a pull is exerted on said bolt, a nut threaded to the shank of said bolt'and adapted to bear on said casing thereby exerting a pull on said bolt, the radius of curvature of the portion of said casing upon which nut bears being greater than the radius through which said nut swings with respect to said first links.

4. Apparatus as in claim 3 wherein said nut includes a plurality of integral arms extending therefrom, the diameter of the circle described by the ends of said arms when rotated about said bolt being less than the width of said casing across the flat surface thereof.

5. A clamp comprising, a casing, said casing including an integral extension thereof arranged to provide a rigid clamping jaw, a movable jaw pivotally secured within said casing and disposed adjacent said fixed jaw, said fixed and movable jaws forming a bite with each other, a bolt extending into said casing, said bolt having at the outer end thereof means for lifting said clamp, a link extending from the inner end of said bolt to said movable jaw, said link being arranged whereby said movable jaw is urged toward said fixed jaw when a pull is exerted on said bolt, and a nut threaded to the shank of said bolt and adapted to bear on said casing said casing having a bearing surface for said nut so shaped and spaced from the point of connection of said bolt to said link to preclude relative rotation between said bolt and said casing in the plane of said link about said point of connection when said nut engages said bearing surface and said said bolt is pivotally secured connecting said bolt to one ofsaid jaws for reducing the spacing of said jaws when a pull is exerted on said bolt, a nut, said nut being threaded to the shank of said bolt and adapted to bear on an upper portion of said casing, said upper portion of said casing being so shaped and spaced from the point or" connection of said bolt to said linkage to preclude relative rotation between said bolt and said casing in the plane of said linkage about the point of connection of said bolt to said linkage, when said nut bears on said upper portion of said casing and said jaws have a bite on an object to be lifted, and to permit said relative rotation when said nut is free of said upper portion of said casing.

JOHN A. HAGAN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 576,179 Wood Feb. 2, 1897 1,011,660 Strathern Dec. 12, 1911 1,514,983 Monnich Nov. 11, 1924 2,310,869 Racz Feb. 9, 1943 2,848,741 Jessen May 16, 1944 2,360,601 Waldrup Oct. 1'7, 1944 2,386,034 Church Oct. 2, 1945 

